Methods of producing carotenoids by the expression of plant ε-cyclase genes

Abstract

Nucleic acid sequences encoding ∈-cyclase, isopentenyl pyrophosphate isomerase and β-carotene hydroxylase as well as vectors containing the same and hosts transformed with the vectors. Methods for controlling the ratio of various carotenoids in a host and for the production of novel carotenoid pigments. The present invention also provides a method for screening for eukaryotic genes encoding carotenoid biosynthesis, and for modifying the disclosed enzymes.

We claim:  
     
       1. A method of producing or altering the production of at least one carotenoid in a host cell, relative to an untransformed host cell, the method comprising: 
       a) inserting into the host cell a vector comprising a heterologous plant nucleic acid sequence which encodes SEQ ID NO:2, wherein said heterologous plant nucleic acid sequence is operably linked to a promoter; and  
       b) expressing the heterologous plant nucleic acid sequence to produce, enhance, reduce, or otherwise affect the production of carotenoids in the host cell.  
     
     
       2. The method of  claim 1 , wherein the host cell is selected from the group consisting of a bacterial cell, an algal cell, a yeast cell and a plant cell. 
     
     
       3. The method of  claim 1 , wherein the host cell is a photosynthetic cell. 
     
     
       4. A method of producing or altering the production of at least one carotenoid in a host cell, relative to an untransformed host cell, the method comprising: 
       a) inserting into the host cell a vector comprising a heterologous plant nucleic acid sequence which encodes an amino acid sequence that is at least 85% identical to SEQ ID NO:23 or 26, wherein said heterologous plant nucleic acid sequence is operably linked to a promoter; and  
       b) expressing the heterologous plant nucleic acid sequence to produce, enhance, reduce, or otherwise affect the production of carotenoids in the host cell,  
       wherein said heterologous plant nucleic acid sequence encodes a protein having ∈-cyclase activity as depicted in FIG.  2 .  
     
     
       5. The method of  claim 4 , wherein the heterologous plant nucleic acid sequence has a sequence which encodes SEQ ID NO:23 or 26. 
     
     
       6. The method of  claim 4 , wherein the host cell is selected from the group consisting of a bacterial cell, an algal cell, a yeast cell and a plant cell. 
     
     
       7. The method of  claim 4 , wherein the host cell is a photosynthetic cell. 
     
     
       8. A method of producing or altering the production of at least one carotenoid in a host cell, relative to an untransformed host cell, the method comprising: 
       a) inserting into the host cell a vector comprising a heterologous plant nucleic acid sequence which encodes SEQ ID NO:25, wherein said heterologous plant nucleic acid sequence is operably linked to a promoter; and  
       b) expressing the heterologous plant nucleic acid sequence to produce, enhance, reduce, or otherwise affect the production of carotenoids in the host cell.  
     
     
       9. The method of  claim 8 , wherein the host cell is selected from the group consisting of a bacterial cell, an algal cell, a yeast cell and a plant cell. 
     
     
       10. The method of  claim 8 , wherein the host cell is a photosynthetic cell.